Glossary A–ZLetter H
HDMI
HDMI is the widespread digital interface that carries picture and sound over one cable from a source such as a media player to a display.
It exists in several versions that differ in bandwidth, highest resolution and refresh rate. Almost every signage display has at least one HDMI input.
In screen networks, HDMI usually connects the external player to the display; stick players plug directly into the socket. When connected, the devices exchange information about which resolutions the display supports. If something goes wrong, the player shows a wrong resolution or no picture at all. Protected content also requires copy protection that every device in the chain must support.
Operators should look closely at long cables, splitters and adapters, because this is where most picture failures arise. For longer distances there are active and optical cables or HDBaseT. A standard HDMI plug has no latch and can work loose through vibration or pulling; retaining clips or strain relief help. The cable must also suit the required version.